The thermal management of laptop computers and other portable or handheld electronic devices has become increasingly challenging as these devices have become more powerful, while at the same time decreasing in size and weight. In particular, acceptable thermal management solutions for these devices are subject to stringent size and weight constraints, and yet must dissipate a sufficient amount of thermal energy to maintain the components and external surfaces of the device within suitable operating and ergonomic temperature ranges, respectively.
Battery modules have emerged as a particularly challenging component of electronic devices from a thermal management perspective. As portable and hand-held devices have become more powerful, battery modules are required to provide increasing power loads, and have also become more compact. Consequently, battery modules have evolved into increasingly intense hot spots within such devices.
Unfortunately, the placement of battery modules in laptops and handheld devices frequently makes them inaccessible to conventional thermal management schemes that rely on global forced air flow through the device. In particular, the battery module is often sealed off from other components of the device to protect those components in the event of battery leakage. Moreover, since the operation of batteries is typically exothermic, it is necessary to shield the components of a device from the heat generated by the battery module. On the other hand, conventional thermal management systems that rely on convection currents generally provide an insufficient level of heat dissipation to be suitable for this application.
The use of fan-based systems is a common global thermal management solution for desk top computers and other large electronic devices. However, the use of fans is precluded in many portable or handheld electronic devices due to the size and weight constraints noted above, and is also unfavorable from an acoustical perspective. Moreover, even in larger portable electronic devices such as laptops where these constraints are less stringent and where small fan units can be utilized to provide global cooling, these units generally provide insufficient heat dissipation for battery modules and other intense hotspots within the device.